Fix bugs and pass JSON tests for responses

include/mtx/responses/public_rooms.hpp

@@ -53,7 +53,7 @@ struct PublicRoomsChunk
     //! Aliases of the room. May be empty.
     std::vector<std::string> aliases;
     //! The canonical alias of the room, if any.
-    std::string canonical_alias;
+    std::string canonical_alias = "";
     //! The name of the room, if any.
     std::string name;
     //! **Required.** The number of members joined to the room.

lib/structs/responses/public_rooms.cpp

@@ -7,7 +7,7 @@ namespace mtx {
 namespace responses {
 
 void
-from_json(const nlohmann::json &obj, RoomVisibilityResponse &res)
+from_json(const nlohmann::json &obj, RoomVisibility &res)
 {
     res.visibility = stringToVisibility(obj.at("visibility").get<std::string>());
 }
@@ -15,23 +15,23 @@ from_json(const nlohmann::json &obj, RoomVisibilityResponse &res)
 void
 from_json(const nlohmann::json &obj, PublicRoomsChunk &res) 
 {
-    res.aliases = obj.at("aliases").get<std::vector<std::string>>();
+    res.aliases = obj.value("aliases", std::vector<std::string>{}); 
 
-    res.canonical_alias = obj.at("canonical_alias").get<std::string>();
+    res.canonical_alias = obj.value("canonical_alias", std::string{});
 
-    res.name = obj.at("name").get<std::string>();
+    res.name = obj.value("name", std::string{});
 
     res.num_joined_members = obj.at("num_joined_members").get<int>();
 
     res.room_id = obj.at("room_id").get<std::string>();
 
-    res.topic = obj.at("topic").get<std::string>();
+    res.topic = obj.value("topic", std::string{});
 
     res.world_readable = obj.at("world_readable").get<bool>();
 
     res.guest_can_join = obj.at("guest_can_join").get<bool>();
 
-    res.avatar_url = obj.at("avatar_url").get<std::string>();
+    res.avatar_url = obj.value("avatar_url", std::string{});
 }
 
 void
@@ -40,11 +40,17 @@ from_json(const nlohmann::json &obj, PublicRooms &publicRooms)
     // PublicRoomsChunk is CopyConstructible & DefaultConstructible
     publicRooms.chunk = obj.at("chunk").get<std::vector<PublicRoomsChunk>>();
     
-    publicRooms.next_batch = obj.at("next_batch").get<std::string>();
+    if (obj.count("next_batch")) {
+        publicRooms.next_batch = obj.at("next_batch").get<std::string>();
+    }
 
-    publicRooms.prev_batch = obj.at("prev_batch").get<std::string>();
+    if (obj.count("prev_batch")) {
+        publicRooms.prev_batch = obj.at("prev_batch").get<std::string>();
+    }
 
-    publicRooms.total_room_count_estimate = obj.at("total_room_count_estimate").get<int>();
+    if (obj.count("prev_batch")) {
+        publicRooms.total_room_count_estimate = obj.at("total_room_count_estimate").get<int>();
+    }
 }
 
 } // namespace responses